Webmail(Horde) slow

If the webmail (horde) is getting slow, the common reasons are:

1. Too many filters/white-lists and blacklists

2. Mailbox is too large, contains huge number of emails

3. Too many users logged into Horde simultaneously.

If these are not the case, then :

1. Disable 'CRAM-MD5' by removing "AUTH=CRAM-MD5" from '/etc/courier-imap/imapd' file in the line:

IMAP_CAPABILITY="IMAP4rev1 UIDPLUS CHILDREN NAMESPACE THREAD=ORDEREDSUBJECT THREAD=REFERENCES SORT QUOTA AUTH=PLAIN IDLE"

2. Restart courier-imap:

# /etc/init.d/courier-imap restart

This will fix the issue.


For Windows:

1. Replace Imap key in registry:

HKEY_LOCAL_MACHINE\SOFTWARE\Mail Enable\Mail Enable\Services\IMAP\Extensions
from:
IMAP4 AUTH=LOGIN IDLE CHILDREN AUTH=CRAM-MD5
to:
MAP4 AUTH=LOGIN CHILDREN AUTH=CRAM-MD5

2. Restart Mail services

Refer ticket: 1202865

 

It is very unsafe to disable CRAM-MD5.

Because now you have a security violation against your users and mail-accounts.
You got to secure your mail-server against people who wants to attack and hack your mail-server(s).

My advice will be, "Do not remove CRAM-M5 validation at IMAP and POP3" unless if it's necessary
Normally this function should be removed by Parallels itself, if CRAM-MD5 is out of date.

See also what CRAM-MD5 means.